Manufacture of alcohols



Nov. 19, 1935. F. J. METzGER MANUFACTURE OF ALCOHOLS Filed Feb. 8, 1932 INVENTOR BY PM M mwa. Ww.

ATTORNEYS Patented Nev. 19, 1935 UNITED STATES MANUFACTURE 0F ALCOHOLS Floyd J. Metzger, New York, N. Y., signor to Air Reduction Company, Incorporated, New York, N. Y., a corporation of New York Application February 8, 1932, Serial No. 591,591 Renewed May 21, 1934 13 Claims. (Cl. 260-156) and to an improved apparatus for such production.

According to the process oi' such prior applications alcohols are produced continuously by passing the alkylene hydrocarbons, such as ethylene, etc. in admixture with suitable proportions of steam into intimate contact with an acid catalyst and particularly a sulfuric acid catalyst while maintaining the catalyst at a high temperature and maintaining the gases under a high pressure, with resulting conversion of the alkylene hydrocarbons into alcohol which is subsequently condensed. The process is advantageously carried out in a cyclic manner by maintaining a circulating stream of e. g. ethylene under a high pressure, admixing therewith steam in suitable proportions, passing the resulting mixture through or into contact with the acid catalyst at a high temperature, condensing the alcohol and excess steam while maintaining the high pressure and recycling the ethylene with suitable further additions of ethylene-and steam in the further carrying out of the process.

In the improved process of the present invention the mixture of alkylene hydrocarbon. e. g., ethylene and steam is formed by vaporizing liquid water in the presence of ethylene with utilization of the heat of the hot gases from the converter to vaporize the water in the presence of ethylene, and with resulting cooling of the hot gases.

I have found that the production of alcohols from alkylene hydrocarbons such as ethylene can be advantageously carried out with, the use of a combined heat interchanger and boiler in which water is boiled or` vaporized in the presence of ethylene by heat interchange with the hot alcohol-containing gases from the converter, with simultaneous cooling of such hot gases and utilization of their heat for generating steam in admixture with ethylene and for superheating the resulting admixed steam and ethylene.

I have further found that with the use of a counter-current heat interchanger and boiler the hot gases from the converter can be sufiiciently cooled, while maintaining them under high pressure, so that condensation of alcohol therefrom can be eiiected, the gases being cooled to a. tempcrature approaching that of the liquid water entering the counter-current heat interchanger and boiler; and that the water can` be vaporized in admixture with the ethylene and the resulting admixed steam and ethylene superheated to a temperature approaching that of the hot gases coming from the converter, thus accomplishing simultaneously the cooling of the hot gases and 5 condensation of the alcohol therefrom and the conversion of water into steam admixed with thyleneand superheating of the resulting mixure.

'Ihe use oi' such a combined heat interchanger l0 and boiler has important advantages in the process. The use of liquid water, particularly in a countercurrent heat interchanger, enables the hot alcohol-containing gases to be cooled to a temperature approaching that of the water so l5 that a large part of the alcohol can be condensed therefrom. The introduction of liquid water enables the amount of water to be exactly regulated, enables the heat interchanger to act as a boiler as well as a heat interchanger, and permits utili- 20 zation of the heat of the alcohol-containing vapors from the converter for generating steam for use in the process. The introduction oi' ethylene in admixture with the water, or the vaporizing of the water in the presence of ethylene, lowers the boiling point of the water so that, even under the high temperatures used in the process, the water will be converted into steam at a temperature far below its normal boiling point under such pressure, owing to the partial pressure effect of the ethylene. The large amount of heat contained in the hot alcohol-containing gases from the converter can thus be utilized to advantage in generating steam admixed with ethylene and superheating the resulting mixture and, with a suitable countercurrent heat interchanger the alcohol-containing vapors are cooled to a low temperature so that alcohol is condensed therefrom under the high pressures used in the process. Such a countercurrent heat interchanger thus serves both as a boiler and as a condenser, enabling a marked economy to be obtained in the heat required for carrying on the process and particularly for vaporizlm the water and forming steam. 'Ihe steam and ethylene can, moreover, be 45 superheated to a temperature approaching that of the converter so that only a relatively small amount of additional heat is required for further heating the gases to the temperature required in the converter.

The present process can advantageously be carried out in a cyclic manner, with recirculation of the ethylene, after the condensation of alcohol therefrom, and with admixture of liquid water with the recycled ethylene, and the addition of sure, is small.

ethylene to make up for that converted to alcohol in the process. In such a cyclic process, carried out under a high pressure, the recirculating ethylene can be maintained under a uniform high pressure, the alcohol can be condensed therefrom under such pressure, and the water can be converted into steam under such. pressure but at a much lower temperature than would be required in a steam boiler operating at such pressure.

The present process can be carried out at such pressures as are referred to in my said prior applications, for example, at 600 pounds pressure, or at 1000 pounds pressure, or at 2000 pounds pressure, or at higher or lower or intermediate pressures. The process is of particular advantage at high pressures around 1000 or 2000 pounds or higher where it is diiiicult to generate steam in a steam boiler at such high pressures, but where the generation of steam can readily be accomplished in the presence of ethylene at temperatures far below those of such a steam boiler, and at temperatures below those of the hot alcohol-containing vapors from the converter, therebyutilizing the heat of such hot .gases for generating steam admixed with ethylene even at such high prescures.

The proportions of steam and ethylene used in the process can be varied, and can be regulated by regulating the amount of water pumped into the apparatus and vaporized therein in proportion to the ethylene gas present during the vaporization of the water.

While the present process can be carried out without recycling of the ethylene, and by supplying fresh ethylene and water to the heat inter-- changer boiler, in proper proportions, the process is advantageously carried out as a cyclic process, with recirculation of the ethylene, after condensation of alcohol therefrom, and with admixture of fresh ethylene to make up for that converted into alcohol in the cyclic process.

The heat interchanger-boiler used in the present process and apparatus can vary in its construction. The ethylene can be bubbled or forced through or over water in a boiler, heated by the hot alcohol-containing gases from the converter,

supplemented by additional heat if necessary.'

But it is more advantageous to utilize a countercurrent heat interchanger which will serve both as a boiler for converting water into steam admixed with ethylene and as a condenser for cooling the alcohol-containing gases to condense alcohol therefrom.

The power consumption required in the operation of the present process and apparatus, particularly when the ethylene or other alkylene gas is recycled and maintained under a uniform pres- A gas circulating pump readily keeps the ethylene circulating at the desired rate. An ordinary water pump enables water to be supplied at an easily regulated rate to the system. An additional ethylene can readily be supplied, under the necessary pressure, to make up for that converted into alcohol, and for such amount as may be released from the system for purging prposes.

The admixed ethylene and steam from the heat interchanger can be further heated to bring them to the temperature required in the converter by a suitable superheater arranged between the heat interchanger and converter, heated in any suitable manner, advantageously by a superheater heated by diphenyl oxide vapors. The cooled alcohol-containing gases from the heat interchanger can be further cooled, before recycling the by indirect contact with cold water. 5

As pointed out in my prior applications, the temperature employedin the converter, the strengh of the acid catalyst, the 'pressureand the ratio of steam to ethylene are more or less interdependent and should be regulated and corre- 1o lated. In general it is advantageous to use an amount of steam equal to or somewhat in excels of the ethylene, for example, a volume ratio of steam to ethylene entering the converter of around 55 to 45. y The catalyst is advantageously 15 a dilute sulfuric acid catalyst using, for example, sulfuric acid having initially a concentration of around 15 to 30% sulfuric acid (H2804) and a temperature range from about 250 to around 300 C. It is probable that, during the process, zo some alkyl sulfate or sulfates are formedso that the catalyst is a mixture of sulfuric-acid andalkyl sulfate or sulfates. Promoters can be employed in admixture with theacid catalyst.

The invention will be further described in-con- 25 nection with the accompanying drawing, which illustrates in a somewhat conventional and -diagrammatic manner apparatus embodying the.l invention and adapted forl the. practice offthe process of the invention. y 30 In the accompanying drawing .provision is made for recycling the ethylenewhile maintaining it under high pressure and for supplying additional eythlene as required to make up for that.co n verted into alcohol and released from the;s ysten i. 35

The additional ethylene is supplied through the pipe I and admixed with the recycled ethylene recycled through the pipe 2, the admixed gases then passing through the meter 3.- and having water admixed therewith from thewatersupply 40 pipe4andpump5.

The admixed ethylene andlwater enter counter-current heat interchanger i at the bottom and pass upwardly therethrough in the space surrounding the inner pipes through which the 4 5 hot alcohol-containing gases pass. Hera owing to heat interchange between the hot gases from the converter and the cool ethylene and water, the water is heated andvaporized in the presence of ethylene and the resulting admixed .steam and 5 0 ethylene are preheated, the admixed gasesescaping through the pipe 'I to the superheater 8,where they are further heated and then passed through the pipe 9 to the converter I0 containing .hesulfuric acid catalyst, and which may itself beheat- 55 ed or cooled to maintain it at the desired temperature, although, with proper regulation 'of the' temperature of the entering gases, and suitable insulation of the converter provision for heating or cooling may be unnecessary. e0

From the converter I0 the alcohol-containing vapors pass through the pipe II to the heat interchanger G where they pass throughthe inner pipe surrounded by the steam and ethyleney or by the water and ethylene and serve to convert 05 the water into steam and to superheat the steam and ethylene. The alcohol-containing vaporsare themselves cooled to atemperature approaching that of the. water and ethylene entering the heat interchanger with resulting condensation of al` 70 cohol. The cooled gases pass through the pipe I2 to the separator i3, where the condensed alcohol is removed and from which itis drawn olf through the cooler Il and pipe I5 in the form f aqueous alcohol, containing, for example, 20% or 75 more of alcohol. The gases from the separator I3 pass through the pipe I6 to a. cooler I1 in which the gases are further cooled by indirect contact with cool water entering at 34 and leaving at 35. Here additional alcohol and water are condensed and pass together with the uncondensed gases through the lpipe I8 to the trap I9 from which the condensed alcohol and water are drawn off at 20 and from which the ethylene is recycled through the pipe 2|, the equalizing chamber 22, pipe 23, recirculating pump 34, pipe 25, equalizing chamber 26, and line 21 for admixture with fresh ethylene and water in the further carrying out of the process.

The recirculating pump for the ethylene is shown with equalizing chambers to promote uniformity of flow of the circulating ethylene but it will be evident that any suitable recirculating means or pump can be employed.

The Water supply for the process is shown as entering through the pipe 29, illter 30, the pipe 3|, meter 32 and pipe 33 to the pump 5 from which the water is pumped through the line I for admixture with the ethylene entering the hea*J interchanger.

In the carrying out of the process the conditions of operation, such as the temperature of the converter, the strength of the acid catalyst, the proportion of steam and ethylene, and the pressure, should be correlated and, when equilibrium has been reached, the process can then be continued under substantially uniform conditions. The amount of steam supplied can be regulated by the amount of water pumped into the apparatus, and the proportions of steam and ethylene can be regulated either by regulating the rate at which Water is supplied or by regulating the rate of recirculation of the ethylene. Some of. the recirculating ethylene can be withdrawn continuously or periodically through the relief line 28 with corresponding increase in the amount of fresh ethylene added to the cycle.

As an example of the practice of the process, there was obained about 1 gallon per hour of pure alcohol in the form of a 20% aqueous solution for each 5 gallons per hour of water introduced and for each thousand feet of gas cycled' per hour, when operating at a pressure of about 1000 pounds and a temperature in the converter of around 250 to 260 C. and with the'dilue sulfurie acid catalyst in equilibrium under the temperature, pressure. and steam-ethylene ratio employed and with the use of about 2 liters of acid catalyst per liter of alcohol (100% alcohol) produced per hour.

As an example of the heat interchange obtained in the combined heat exchanger-boiler-condenser, with the cold water supplied at about 30 C. and with the admixed Water and ethylene entering the exchanger at about 32 C. the resulting admixed steam and ethylene leaving the exchanger was superheated to a temperature of about 219" C. and was further superheated in the diphenyl oxide superheater to a temperature of about 249 C. before entering the converter. 'I'he hot alcohol-containing gases leaving the converter entered the heat interchanger at a temperature of about 245 C. and were cooled therein to a temperature of about 62 C. Under such conditions the heat of the hot alcohol-containing gases from the converter was sufficient to convert the water into steam and to superheat the steam and ethylene while the hot gases were themselves cooled to condense a considerable part of the water and alcohol therefrom.

The superheating of the steam alud ethylene in the superheater 8 can readily be accomplished by the use of diphenyl oxide vapors generated in J a boiler (not shown) and entering and leaving the superheater at 36 and 31 respectively, thereby 5 flowing countercurrent to the steam and ethylene mixture.

While the process has been described more particularly in-connection with the produciion of ethyl alcohol from ethylene, other alkylene hy- 10 drocarbons, ysuch as propylene, etc. can be similarly employed and iso-propyl or other alcohols similarly produced. It will also be understood that variations and modications can be made in the specific process and apparatus described and illustrated without departing from the spirit and scope of the invention.

I claim:

1. The method of producing alcohols in a continuous manner which comprises supplying wal ter and alkylene hydrocarbon to a combined boiler and heat interchanger and heating the same therein to vaporize the water to formia mixture of steam and alkylene hydrocarbon, passing the resulting mixture into intimate contact with an acid catalyst maintained at an effective catalytic strength and temperature and under a high pressure with resulting formation of alcohol and passing the resulting hot alcohol-containing gases through the heat interchanger while under a similar high pressure to effect heating of the water and alkylene hydrocarbon and conversion of the water into steam and simultaneous cooling of the hot gases, the conversion of the water into steam being eiected at a high pressure in the presence of the alkylene hydrocarbon at a temperature materially lower than its boiling point under the prevailing high pressure.

2. The method of producing alcohols in a continuous manner which comprises supplying water and alkylene hydrocarbon in regulated proportions and under a high pressure to va countercurrent heat interchanger and heating the same therein to vaporize the water in the presence of the alkylene hydrocarbon, passing the resulting steam and alkylene hydrocarbon into intimate contact with an acid catalyst maintained at an effective catalytic strength and temperature and under a high pressure with resulting formation of alcohol, and passing the resulting alcoholcontaining gases through the heat interchanger countercurrent to the water and alkylene hydrocarbon, with resulting cooling of such gases and condensation of alcohol therefrom under a high pressure simultaneously with the heating of the water and conversion thereof into steam admixed with alkylene hydrocarbon while under a similar high pressure. i

3. The method of producing alcohols in a continuous manner which comprises supplying a mixture of water and alkylene hydrocarbon to a heatinterchanger and heating the same therein under a high pressure to vaporize the water in the presence of alkylene hydrocarbon and to superheat the resulting admixed steam and hydrocarbon, further heating the resulting steam and hydrocarbon and passing the same into intimate contact with an acid catalyst maintained at an eifective catalytic strength and temperature and under a high pressure, and cooling the resulting alcohol-containing gases by passing the same while under a similar high pressure through said heat interchanger countercurrent to the steam and alkylene hydrocarbon and to the water and alkylene hydrocarbon with resulting cooling of the gases and condensation of alcohol there'- from simultaneously with the heating of the water and hydrocarbon and of the resulting steam and hydrocarbon mixture while under a similar high pressure.

4. The cyclic process of producing ethyl alcohol in a continuous manner which comprises .admixing recycled ethylene with fresh ethylene and with water, passing the resulting mixture through a countercurrent heat interchanger in indirect contact with hot gases hereafter referred to to effect heating of the water and hydrocarbon and vaporization of the water in admixture with the hydrocarbon and superheating of the resulting admixed steam and hydrocarbon, passing the resulting steam and hydrocarbon into intimate contact with an acid catalyst maintained at an effective catalytic strength and temperature and under a high pressure with resulting -formation of alcohol, and passing the hot alcohol-containing gases through the countercurrent heat interchanger in indirect contact with the steam and hydrocarbon and with the water and hydrocarbon to heat the same with simultaneous cooling of the gases to condense alcohol therefrom, and

recycling the ethylene in the further carrying out of the process, the ethylene and admixed water, steam and alcohol being maintained under a high pressure throughout the cyclic process.

5. 'I'he method of producing ethyl alcohol in a continuous manner from ethylene which comprises supplying water and ethylene in regulated proportions and under a high pressure to a countercurrent heat interchanger and heating the same therein to vaporize the water inthe presence of the ethylene, passing the resulting steam and ethylene into intimate contact with a dilute sulfuric acid catalyst maintained at an eilective catalytic strength and temperature and under a high pressure with resulting formation of ethyl alcohol, and passing the resulting alcohol-containing gases while under a similar high pressure through the heat interchanger countercurrent to the water and ethylene with resulting cooling of such gases and condensation of alcohol therefrom simultaneously with the heating of the water and conversion thereof into steam admixed with ethylene while under a similar high pressure.

6. The method of producing ethyl alcohol in a continuous manner which comprises supplying a mixture of water and ethylene to a heat interchanger under a high pressure and heating the same therein to vaporize the water in the presence of ethylene and to superheat the resulting admixed steam and ethylene, further heating the resulting steam and ethylene and passing the same into intimate contact with a dilute sulfuric acid catalyst maintained at an effective catalytic strength and temperature and under a high pressure, and cooling the resulting alcohol-containing gases by passing the same while under a similar high pressure through said heat interchanger countercurrent to the steam and ethylene and to the water and ethylene with resulting cooling of the gases and condensation of ethyl alcohol therefrom simultaneously with the heating of the water and ethylene and of the resulting steam and ethylene mixture while under a similar high pressure.

7. The further improvement in the process of claim 5 in which the gases leaving the interchanger and after separation of alcohol therefrom are further cooled to condense additional alcohol therefrom and in which the resulting acentosv ethylene gas is recycled and admixed with fresh ethylene and with water in the further carrying out of the process.

8. The method of producing alcohols in a continuous manner which comprises supplying water 5 and alkylene hydrocarbon to a combined boiler and heat interchanger and heating the same therein to vaporize the water to form a mixture of steam and alkylene hydrocarbon, passing the resulting mixture hito intimate contact with a catalyst maintained at an effective temperature and under a high pressure with resulting formation of alcohol and passing the resulting hot alcobol-containing gases through the heat interchanger while under a similar-high pressure to eect heating of the water and alkylene hydrocarbon and conversion of the water into steam and simultaneous cooling of the hot gases, the conversion of thewater into steam being effected at a high pressure in the presence of 'the alkylene hy- 20 drocarbon at a temperature materially lower than its boiling point under the prevailing high pressure.

9. The method of producing alcohols in a continuous manner which comprises supplying water andv alkylene hydrocarbon in regulated proportions and under a high pressure to a countercurrent heat interchanger and heating the same therein to vaporize the water in .the presence o: the alkylene hydrocarbon, passing the resulting steam and alkylene hydrocarbon into intimate contact with a catalyst maintainedv at an effective temperature and under a high pressure with resulting formation of alcohol, and passing the resulting alcohol-containing gases through the heat interchanger countercurrent to the water and a1- kylene hydrocarbon, with resulting cooling of such gases and condensation of alcohol therefrom under a high pressure simultaneously with the heating of the water and conversion thereof into steam admixed with alkylene hydrocarbon while under a similar high pressure.

10. The method of producing alcohols in a continuous manner which comprises supplying a mixture of water and alkylene mdrocarbon to a heat'45 interchanger and heating the same therein under a high pressure to vaporize the water in the presence of alkylene hydrocarbon and to superheat the resulting admixed steam and hydrocarbon, further heating the resulting steam and hydrocarbon and passing the same into intimate contact with a catalyst maintained at-an effective temperature and under a high pressure, and cooling the resulting alcohol-containing gases by passing the same while under a similar high pressure through said heat interchanger countercurrent to the steam and alkylene hydrocarbon and to the water and alkylene hydrocarbonwith resulting cooling of the gases and condensation of alcohol therefrom imder a high pressure simultaneously with the heating of the water and hydrocarbon and of the resulting steam and hydrocarbon mixture while under a similar high pressure,

11. The cyclic process of producing ethyl alcohol in a continuous manner which comprises admixing recycled ethylene with fresh ethylene and with water, passing the resulting mixture through a countercurrent heat interchanger in indirect contact with hot gases hereafter referred to to effect heating of the water and hydrocarbon and vaporization of the water in admixture with the hydrocarbon and superheating of the resulting admixed steam and hydrocarbon, passing the resulting steam and hydrocarbon into intimate contact with a catalyst maintained at an effective temperature and under a high pressure with resulting formation of alcohol, and passing the hot alcohol-containing gases through the countercurrent heat interchanger in indirect contact with the steam and hydrocarbon and with the water and hydrocarbon to heat the same with simultaneous cooling of the gases to condense alcohol therefrom, and recycling the ethylene in the further carrying out of the process, the ethylene and admixed water, steam and alcohol being maintained under a high pressure throughout the cyclic process.

12. The method of producing ethyl alcohol in a continuous manner from ethylene which comprises supplying water and ethylene in regulated proportions and under a high pressure to a counter-current heat interchanger and heating the same therein to vaporize the water in the presence of the ethylene, passing the resulting steam and ethylene into intimate contact with a catalyst maintained at an eiIective temperature and under a high pressure with resulting formation of ethyl alcohol, and passing the resulting alcoholcontaining gases while under a similar high pressure through the heat interchanger countercurlcontinuous manner which comprises supplying a mixture of water and ethylene to a heat interchanger and heating the same therein to vaporize the water in the presence of ethylene and to super-heat the resulting admixed steam and ethy' iene, further heating the resulting steam and ethylene and passing the same into intimate contact with a catalyst maintained at an effective temperature and under a high pressure, and cooling the resulting alcohlol-containing gases by passing the same while'under a similar high pressure through said heat interchanger count'erourrent to the steam and ethylene and to the water and ethylene with resulting cooling of the gases and condensation of ethyl alcohol therefrom simultaneously with the heating of the water and ethyiene and of the resulting steam and ethylene mixture.

FLOYD J. METZGER. 

